Association between craniomandibular disorders and occlusal interferences

No theoretical model explaining craniomandibular disorders has been generally accepted, despite the large number of studies on its etiology. This article suggests that one reason for the lack of a well-structured causal explanation could be associated with the study design most often used: cross-sectional studies of samples representative of a base population. Variation in the number of interferences was increased among the subjects by eliminating occlusal interferences annually in the treatment group (n = 53). The control group (n = 46) underwent placebo treatment. A double-blind design was used throughout the 3-year study. A cross-sectional analysis in the third year disclosed a significant association between the number of interferences and the signs of craniomandibular disorders. The results suggest that the absence of interference-free subjects in nonselected samples can be one explanation for the lack of association reported in most studies.